Sweet and sour pork and sweet and sour chicken are Chinese dishes of pork and chicken dipped in batter and fried in oil. The process of preparing these Chinese dishes utilizes two vessels. One vessel is typically a bowl containing a batter mixture of water, a grain flour, and food pieces such as pieces of meat or vegetables. The second vessel is typically a wok containing hot oil.
The batter-dipped food pieces or articles are dropped into a wok, and initially sink until the batter about the food pieces expands whereupon the food articles become floatable and rise to the surface of the oil. The food particles then are fried on the surface of the oil for several minutes or until they turn a certain shade of brown.
The conventional deep fry process has a number of problems. First, the process is slow, troublesome and very inefficient. This is caused for the most part by the manual labor involved. The pieces of food are hand-dipped into the batter, transferred by hand to the wok one by one, turned over manually in the wok, monitored visually in the wok, and removed from the wok by hand.
A second problem is that the conventional dipping and deep frying process is very messy. The liquid-like batter drips as the food pieces are being transferred manually from the batter to the wok. The batter drips onto surfaces between the batter bowl and the wok, and into the wok itself. Batter dripping into the wok not only creates a mess, but lowers the temperature of the oil, and absorbs and thus wastes oil. These drips occupy space on the surface of the oil that otherwise may be used for food pieces. Furthermore, the drips when cooked mingle with the food pieces and must ultimately be separated from the food pieces to create an appetizing and appealing dish.
A third problem is that the manual deep fry process may produce food pieces which stick together and which hence are more difficult to eat. The food pieces become joined to each other as a result of contact between the pieces within several seconds after being dropped into the oil. During this time, a shell is formed about the batter-dipped food piece, and this shell forms about and joins any pieces which are sticking together by virtue of the sticky batter. This problem is compounded by the conventional method of dropping the pieces into the hot oil. After the pieces have dropped into the oil, the pieces initially sink under the inertia of the fall, but then expand under the influence of the heat of the oil and consequently rise to float on the surface of the oil. As the pieces rise to the surface, they may come into contact with other pieces from below, which then may permit a common shell to be formed about the two pieces.
A fourth problem is that the food pieces may be undercooked or overcooked. This may be caused by the difficulty in judging how much time each individual food piece has been frying in the oil as the food pieces are typically dropped one by one into the wok over a period of time but removed at the same time. This problem may also be caused by one-half of the food piece being submerged and the upper half remaining above the oil. This may also be caused by uneven oil temperatures in the wok.
A fifth problem relates to safety. The conventional Chinese deep fry process causes an oil mess and particularly produces a great quantity of bits of batter. This environment lends itself to accidents, such as combustion of the drips of batter. Moreover, pouring large quantities of oil into and pouring large quantities of hot oil from the conventional commercial wok is dangerous.
A sixth problem is hygiene. Food is hand-dipped into the batter, transferred by hand to the wok, and manually removed from the wok. Furthermore, the heat from the oil and vapor creates a hot working environment in which the attendant cook may sweat profusely.
A seventh problem is that, even with relatively large woks, the area for deep frying is small. Only the surface of the oil is used for frying.
An eighth problem is the conventional Chinese deep frying process occupies a relatively great amount of kitchen space and takes a relatively great amount of time. Hence, Chinese dishes may not be prepared during the busy hours, but are typically cooked in advance, which then undesirably requires the dishes to be cooked a second time for the customer
A ninth problem is the conventional Chinese deep fry process requires a skilled cook, who may be difficult to find. Furthermore, this job is undesirable for most people.
A tenth problem is the cost of labor. Even skilled cooks must work long hours. Moreover, the cost of batter loss and oil loss contributes to the waste. Oil loss may be caused by high temperature deterioration.